Association of IL-6 polymorphisms with gastric cancer risk: evidences from a meta-analysis

The findings of associations between IL-6 polymorphisms and risk of gastric cancer are controversial. We conducted a meta-analysis of the IL-6 gene to provide evidences for the current understanding of the genetic association with gastric cancer. We searched for relevant studies without language restriction in PubMed, EMBASE and Cochrane Library published up to November 2011. The strengths of the associations between IL-6 polymorphisms and gastric cancer risk were estimated by odds ratios (OR) with 95% confidence interval (95% CI). We identified seven case-control studies involving 1364 gastric cancer cases and 1748 controls for the analysis. Because of limited eligible data, our meta-analysis specifically focused on three SNPs of the IL-6 gene, -174 G/C, -572 G/C and -597 G/A. We found no significant associations of IL-6-174 G/C, -572 G/C and -597 G/A polymorphisms with gastric cancer risk in the overall population (all p>0.05). Subgroup analysis did not show significant associations in Asian population or Caucasian population either (all p>0.05). Begg's test and Egger's test suggested no evidence of publication (all p>0.05). Our findings showed that polymorphisms of IL-6-174 G/C, -572 G/C and -597 G/A are not associated with gastric cancer risk. However, the results should be interpreted with caution due to the limited number of studies available.